DTMF tone duration on MC series modem

I want to increase the DTMF duration on MC series modem using at command AT+VTD= on WCDMA/3G network. Command executes fine but does not have any effect. The DTMF duration sent from module remain the same. Questions:

  1. How to increase DTMF duration using SDK/AT command?
  2. How to find what is the current DTMF duration and time between two DTMF tones?

Thanks !

how about trying the QMI SDK API?

#include “qaGobiApiVoice.h”
BYTE dtmfCallId = 1;
void DTMF_Start(BYTE input)

voiceContDTMFinfo objvoiceContDTMFinfo;

objvoiceContDTMFinfo.pCallID =&dtmfCallId;
objvoiceContDTMFinfo.DTMFdigit = input;

        ULONG nRet = SLQSVoiceStartContDTMF( &objvoiceContDTMFinfo );

if ( eQCWWAN_ERR_NONE != nRet )
printf(“ERROR!!! DTMF_Start nRet=%ld\n”,nRet);

void DTMF_Stop()

voiceStopContDTMFinfo objvoiceStopContDTMFinfo;

objvoiceStopContDTMFinfo.callID =dtmfCallId;

        ULONG nRet = SLQSVoiceStopContDTMF( &objvoiceStopContDTMFinfo );

if ( eQCWWAN_ERR_NONE != nRet )
printf(" ERROR!!! DTMF_Stop nRet=%ld\n",nRet);



@jyijyi Thanks. I have tried using these API. However, I am subscribing the DTMF event callback using SLQSVoiceSetDTMFEventCallBack() which occurs on the fixed interval. And, I like to tune that interval. any pointers?

no, i don’t see any pointer for that purpose.

Have you tried API SLQSVoiceBurstDTMF()? Not sure if this works.

@jyijyi I think SLQSVoiceBurstDTMF() is only for CDMA network